What is the GM diet?
The General Motors – or GM – diet has been making plenty of headlines recently but it’s been around since the 1980s. It’s said that the unconventional eating plan was used by the car company to encourage its employees to stay in shape (but GM has since disputed those origins).
The content and quantity of the eating planning varies from day to day, but one thing remains consistent – it is simple and it is strict.
Day 1: Fruit. Just fruit. As much as you want. But no bananas. They recommend watermelon or rockmelon.
Day 2: As much raw or cooked vegetables as you want. You can also start the day with a baked potato with oil or butter.
Day 3: Fruit AND vegetables today but no bananas or potatoes.
Day 4: NOW you can have bananas, eight in fact. And three glasses of milk.
Day 5: Two, 280 gram portions of lean beef and six whole tomatoes.
Day 6: Unlimited amounts of lean protein and vegetables.
Day 7: Vegetables, fresh fruit juice and brown rice.
Some versions of the diet also note a signature cabbage soup that can be consumed as much as you’d like throughout the entire week.
What are the results?
Results and testimonials are varied, but some claim that you can lose up to seven kilograms in one week.
What do the experts say?
“This is a great example of a classic fad diet,” says Clare Collins, Accredited Practising Dietitian and Spokesperson for the Dietitians Association of Australia.
“Through the restriction of food groups, you’ll end up significantly cutting down your calories.”
She says that you may well see quick and dramatic results, but it’s not a realistic long term option.
“It would appeal to some people because you don’t have to count calories and it simplifies your thinking,” Clare told Women’s Health.
“Over a week you easily could drop a couple of kilos, sometimes you’re also dropping the energy that is stored in your muscles – that’s called glycogen – and glycogen, it’s like petrol in a car and it’s stored in your muscles with water. So you might get a massive number dropping on the scales that is not necessarily all body fat.”
Are there any side effects?
“In one week are you going to do yourself damage? Probably not, unless you’re on some medication for your health,” Clare says. “If you’re on blood pressure medication or insulin or tablets for type 2 diabetes or thyroid hormones or anything like that, it can undermine those.”
Clare says that you’re not really going to do harm in the short term, and that it might be enough to get people kick started with healthy eating. But it’s not helpful for people who are looking to change their food habits long term.
“It’s not the sort of thing you could live by and I think there are better options.”